Performance evaluation of multi-pixel photon counters for PET imaging

The multi-pixel photon counter (MPPC), also known as the silicon photo-multiplier (SiPM), is a novel, solid-state photodetector that contains an array of Geiger-mode photodiodes (called microcells below) to a gain in range of 10⁵ -10⁶ when operating at a low voltage of 40-70 V. The device also has relatively high photon detection efficiency (PDE) and fast timing response. It is also compact and insensitive to magnetic fields. These properties of the MPPC has recently created substantial interest in using the device for PET imaging. In this paper, we evaluate and compare the performance properties of three designs of 1times1 mm² MPPC offered by Hamamatsu for use in PET. We examine the gains of devices, and also their energy and timing resolutions when coupled to LYSO.